1. Field of the Invention
The present invention relates to a focus detection device, a focus detection method and an imaging apparatus.
2. Description of Related Art
Japanese Laid Open Patent Application No. S57-165806 discloses a focus detection device adopting a split-pupil phase difference detection method. Such a focus detection device converts the extent of relative offset manifested by a pair of images formed with focus detection light fluxes having passed through a pair of areas at an exit pupil of an imaging optical system a defocus amount indicating the extent of defocusing manifested by the imaging optical system by using a specific conversion expression.